Recreational pools such as swimming pools and spas involve considerable plumbing for water recirculation, filtration and heating. Typically synthetic organic plastic piping is used to carry the water. The various pieces of equipment used to process the water such as filters are provided with fittings having connection stubs for attachment of the piping. The mode of coupling the piping to the fittings typically is either by threaded connection between cooperating threaded portions on the parts to be coupled or by gluing slip-slip joints. The former techniques takes more time and requires tape or plumber's sealant to ensure a water tight seal, but threaded couples can be adjusted after first connection for adjustments that may become necessary. Gluing involves putting a solvent on the parts to be interfitted and sliding them together with a slight rotation. This type of joint is usually water-tight, but not always, and may otherwise be not properly adjusted. In case of leakage or maladjustment, the coupling cannot be simply taken apart but must be replaced.